Police in Ha Tinh Province in central Vietnam said Thursday they have proposed criminal charges against three more people, including two forest managers, in the province's largest ever deforestation case.

The suspects were allegedly involved in the logging of nearly 500 cubic meters of timber from protective forests along the Laos border.

The two officials are Bui Van Thao, 49, former head of a forest ranger station, and Nguyen Duy Ty, 27, a forest management employee of the Huong Son Forestry and Service Company.

Phan Huu Huan, the third suspect, is a 42-year-old businessman dealing in timber.

The illegal logging took place between June 2010 and June 2011, but local police said they only noticed it late last year and started recouping the timber early this year.

Investigations showed Thao was among the people who allegedly agreed to let the illegal timber pass his station. He witnessed its transportation on at least one occasion, when 41.7 cubic meters of lumber went through unperturbed.

Earlier, police proposed charges against six other people, including five forest officials and rangers, and another timber dealer named Nguyen Thanh Binh.

One official, Pham Anh Tuan, former head of the Hong Linh forest management board, received VND12 million (US$575) from Huan in exchange for allowing him to move 28.8 cubic meters of illegal lumber out of the forest.

The police have suggested charges of "violations of forest management" and "bribery."

If convicted on the first charge, the men would receive up to three years probation, or face jail terms of six months to three years. Their potential imprisonment could reach up to 12 years if their violations are deemed to have been "organized" or "serious."